Cooper Bussmann FNQ-4 Cartridge Time Delay Fuse 4A 500V

Product Description

The COOPER BUSSMANN FNQ-4 is a cartridge-style, time-delay fuse rated at 4 amps and 500 volts AC with an interrupting capacity of 10 kA. The fuse body is constructed from fiber and features an orange color coding for quick visual identification. At 1.5 inches in overall length and 10.3 mm in diameter, it mounts into a standard fuse holder. Electricians and controls technicians install this fuse to protect low-amperage branch circuits and control panel wiring from overcurrent events. The time-delay characteristic allows brief inrush currents to pass without nuisance tripping while still responding quickly to sustained fault conditions.

The FNQ-4 is suited for general-purpose overcurrent protection in residential, commercial, and light industrial control circuits. Typical applications include motor control centers, HVAC equipment control wiring, transformer secondary protection, and other low-amperage panel configurations where a time-delay response is required. The fuse seats into a compatible fuse holder and is well suited for enclosed panel environments where space and amperage ratings are tightly managed.

Key Features

• Time-delay fuse action tolerates brief inrush without nuisance tripping
• Rated 4 amps at 500 volts AC with 10 kA interrupting capacity
• Fiber cartridge body construction for durability
• Orange color coding for fast visual amperage identification
• CE Certified, CSA Certified, UL Listed 248-14, and RoHS Compliant
• Mounts into standard fuse holders for straightforward replacement

Compatibility

Designed as a general-purpose cartridge fuse replacement for fuse holders accepting a 10.3 mm diameter, 1.5-inch cartridge fuse rated at 4 amps and 500 volts.

Installation Notes

Installation should be performed by a licensed electrician in accordance with applicable NEC requirements. De-energize and lock out the circuit before removing or inserting any fuse. Confirm the fuse holder is rated to accept a 10.3 mm diameter cartridge fuse at the required voltage and amperage before installation. Never replace a fuse with a higher-amperage unit to resolve nuisance tripping.